Siku Quanshu ( 四庫全書)Diaolong (雕龍) is an ultra-large database, consisting of 16 sub-databases, includes the contents of over 28,000 kinds of ancient books, amounts to the volume of 5 billion characters. It covers Chinese and Japanese historical, political, economic, religious, philosophic, literary, ethnic and geographic documents. ULS has purchased one of 16 sub-databases: Siku Quanshu 四庫全書. The Siku Quanshu is the largest collection of books in Chinese history divided in four sections: Jing (經 "Classics") , Shi (史 "Histories"), Zi (子 "Masters") , Ji (集 "Collections"),then divided into 44 sub-categories. It includes 3,462 books with 79,338 chapters.